1. Field of the Invention
The present invention relates to a apparatus for retrieving and displaying the contents of books, newspapers, magazines, drawings or photographs which are stored in electronic, optical or magnetic recording mediums, i.e., an electronic book.
2. Description of the Prior Art
Characters, photographs and drawings are printed on paper to form books, newspapers and magazines. Printing on paper permits visual display of pieces of information, and the art of printing permits a lot of reproduction of the same contents within a relatively short time. Therefore, printing is an excellent mass communication means.
However, the use of paper carries associated high costs, such as in transportation, warehousing and disposal of used paper because of a massive and voluminous amount. In an attempt to save paper material, used paper is reclaimed, but reclaimed paper is of such a poor quality that printing is not permitted. At present forest resources are inevitably wasted to provide paper which can be used for printing.
In the hope of saving forest resources the use of electronic, optical or magnetic recording mediums as a substituted for paper has been taken into consideration. Some examples of such recording mediums are integrated circuit boards (electronic recording medium), compact disks (optical recording medium), floppy disks (magnetic recording medium), magnetic cards (magnetic recording medium), digital audiotape (magnetic recording medium), and laser cards (optical recording medium). These recording mediums require reading means as shown in the following table:
______________________________________ recording medium reading means capacites (equivalent number of pages of the book) IC card exclusive reading means 8K bytes required as is the case (4 pages) with credit cards compact disk CD-ROM drive 12 cm CD CD-ROM 504 megabytes (270,000 pages) floppy disk floppy disk drive 1 megabytes (500 pages) magnetic card cash dispenser and 84 bytes the like (0.022 pages) laser card laser card reader 2 megabytes (1000 pages) ______________________________________
(Each page of a book is assumed to contain 2000 parameters which correspond to 2000 bytes.)
The manner of reading these recording mediums is totally different from the manner of reading books, newspapers or magazines.
A personal computer is used to read compact disks or floppy disks. It has a reading apparatus separate from the display of the computer. Its keyboard must be operated to have access to a desired content in such a recording medium for display. The whole apparatus is large in size, and the associated memory has an increased capacity large enough to permit a reference to or looking at information.
IC cards and magnetic cards are of the same size as credit cards. These recording mediums have a relatively small recording capacity, and are designed for a small scale application. IC cards can be renewed in content, and can be used for the same purpose as credit cards. As for magnetic cards these recording means are used as credit cards or prepaid telephone cards.
Laser cards require a reading apparatus of an increased size, compared with the reading apparatus for magnetic cards.
Electronic, magnetic or optical recording mediums have a variety of applications, but they cannot be used in the same fashion as paper on which characters are printed to convey pieces of information as in books, newspapers or magazines.
The above table shows that floppy disks and laser cards have a recording capacity comparable to books, newspapers or magazines. A compact disk, however, has unnecessarily large or superfluous recording capacity to store the content of ordinary printed matters excluding an encyclopedia. Laser cards are small in size, and have a capacity appropriate for recording information as much as ordinary printed matter. But, disadvantageously laser cards require a large-scale reading apparatus.
An electronic book is proposed which can be used in the same fashion as books, newspapers or magazines. This paperless book must meet the following requirements:
1) sentences, drawings or patterns can be displayed in the same fashion as books, newspapers or magazines;
2) small-sized magnetic or optical recording disks or IC cards which have as much content as a book having several hundred pages, can be read in the same fashion as books.
3) it must be portable in size and weight, and can be carried like a book. A person can read it everywhere.
In an attempt to make the device portable, parts to effect the following functions are eliminated from a personal computer-like object. Stated otherwise, a paperless book can be provided by depriving a personal computer of the following functions:
a) elimination of the need to print displayed contents (no printers required); and
b) elimination of the need to effect complicated reference (no keyboard required for the purpose)
Extra requirements for such a paperless book are:
1) underlining function
Selected portions in the displayed information can be underlined as in books, newspapers or magazines.
2) contextual continuing function
If a sentence continues from page to page, the preceeding part can be shifted to the subsequent part of the sentence on the page now on display.
3) page-turning speed control
Subsequent pages are displayed one after another at intervals.
This interval can be controlled by pushing a selected key like turning over the pages of a book to meet the speed at which the reader reads the displayed pages.
4) Some readers feel bothered when required to push a selected key to turn over pages. Automatic page-turning function can be selected, and then pages will be displayed one after another at regular intervals.
5) Extra characters other than standard ones are required to be displayed, although rare in occurrence.
Storage of all extra characters, however would make the paperless book large beyond a portable size. This rare demand must be satisfied without using an inhibitively large capacity memory.
6) Requirements for composition must be met.
7) When occasions demand, stored pieces of information must be renewed to permit the display of the latest information.